DOC: Update docstring for Index.from_variables() (#11256)

Author: VeckoTheGecko

xarray/core/indexes.py

@@ -83,6 +83,10 @@ def from_variables(
         variables : dict-like
             Mapping of :py:class:`Variable` objects holding the coordinate labels
             to index.
+        options : dict-like
+            Keyword arguments passed to this constructor. Propagated from
+            the ``**options`` argument of :py:meth:`xarray.DataArray.set_xindex`
+            or :py:meth:`xarray.Dataset.set_xindex`.
 
         Returns
         -------